Field of the Invention
The present invention relates to a perovskite ceramic composition, a combined composition containing the perovskite ceramic composition, a method for manufacturing the perovskite ceramic composition, and a method for manufacturing a multilayer ceramic capacitor.
Description of the Related Art
In recent years, small multilayer ceramic capacitors capable of having large capacitances have been widely used.
The multilayer ceramic capacitor has a structure in which, for example, a pair of outer electrodes are disposed on both end surfaces of a multilayer body produced by stacking inner electrode layers with ceramic layers serving as dielectric layers interposed therebetween, that is, a capacitor element, so as to be electrically connected to the inner electrode layers alternately arranged so as to be exposed at opposite end surfaces.
In such multilayer ceramic capacitors, various dielectric ceramic compositions having high dielectric constants, e.g., barium titanate based perovskite ceramic compositions, have been widely used as materials constituting the ceramic layers serving as the dielectric layers.
Regarding such dielectric ceramic compositions, for example, Japanese Unexamined Patent Application Publication No. 2013-227196 proposes a perovskite dielectric ceramic composition containing barium titanate serving as a primary component and at least three types of rare earth elements including Eu, wherein a first rare earth element R1 is at least one selected from the group consisting of Sc, Er, Tm, Yb, and Lu, and a second rare earth element R2 is at least one selected from the group consisting of Y, Dy, Ho, Tb, and Gd.
According to Japanese Unexamined Patent Application Publication No. 2013-227196, the dielectric ceramic composition exhibits small changes in electrostatic capacitance in a wide temperature range of −55° C. to 150° C., high insulation resistance at a high temperature of about 150° C., and an excellent high-temperature load life.
However, a multilayer ceramic capacitor produced using the above-described dielectric ceramic composition in the related art has not been able to always sufficiently satisfy the requirement for high reliability in severe environments.